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WP8: Computational analysis of beta-cell modular organization. EuroDia Meeting Lund, 23-25 February 2009. Sven Bergmann Department of Medical Genetics, UNIL & Swiss Institute of Bioinformatics. http://serverdgm.unil.ch/bergmann. Iterative Signature Algorithm.
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WP8:Computational analysis of beta-cell modular organization EuroDia Meeting Lund, 23-25 February 2009 Sven Bergmann Department of Medical Genetics, UNIL & Swiss Institute of Bioinformatics http://serverdgm.unil.ch/bergmann
Iterative Signature Algorithm • Unsupervised large-scale data analysis tool • Modularizes the expression matrix • Reduction of complexity • Allows for easy data integration • Interactive webtool
Modular Analysis • A block of the reordered expression matrix • Genes and samples have scores • Captures differential co-expression Transcription Module
Gábor Csárdi and Sven Bergmann Computational Biology Group, Department of Medical Genetics, University of Lausanne, Switzerland Modular Analysis of Multi-tissue Gene Expression Data
The Data Set • Coming from WP2, Frans Schuit's group. • C57bl6 mice, plus 7 S/A islet samples • 23 different tissues: adrenal gland, bone marrow, brain, diaphragma, ES cells, eye, fat, fetal, gastrocnemius muscle, heart, islet, kidney, liver, lung, ovary, parotis gland, pituitary gland, placenta, seminal vesicles, small intestine, spleen, testis, thymus. • 3-5 samples/tissue, 89 altogether • 19 islet samples, 8 on high fat diet • After filtering based on variance: 14,540 of 45,101 probesets left on the mouse4302 array
Batch and Tissue Effects Pituary gland Islets
Spearman Rank correlation between 75 Affy mouse 430 2.0 arrays TISSUE (n arrays) High Fat Diet (5) 1 Islets 2 Standard Diet (4) 3 Pancreatic acini (3) 4 Adrenal (3) 5 Brain (3) 6 ES cells (3) 7 Adipose tissue (3) 8 Eye (3) 9 Heart (3) 10 Small intestine (3) 11 Hypothalamus (3) 12 Liver (3) 13 Lung(3) 14 Kidney (3) 15 Parotis gland (3) 16 Spleen (3) 17 Seminal vesicles (3) 18 Testis (3) 19 Thymus (3) 20 Diafragm (3) 21 Skeletal muscle (4) Pituitary gland (5) 22 Bone marrow (4) 23 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Very preliminaryModular Analysis Results • 977 transcription modules were identified • High enrichment by tissues, GO categories, KEGG pathways and transcription factors • Condition plots • Show tissue specific modules http://www2.unil.ch/cbg/Eurodia/isa3-html/maintable.html
Pancreas-Specific Modules(Islets + contaminating exocrine cells) • Example: #49, 35 probes, 27 Entrez genes, 43 conditions, 19 islet samples with positive scores • Many pancreas related genes
Pancreas-Specific Modules • Genes: Gcg, Iapp, Abcc8, Scn9a, Prss2, Pnlip, Ela3, Rab37, Cuzd1, Pnliprp2, Clps, Rnase1, Asb6, Ctrb1, BC039632, B830017H08Rik, A930021C24Rik, 2210010C04Rik, 1810049H19Rik
Pancreas-specific Modules • Module #49 • Differentiates between islets and other tissues
Islet specific GO enrichment P-value # Category 5.03e-7 49 digestion 1.25e-12 10 extracellular region 3.18e-5 20 mitochondrion 1.44e-4 25 proton-transporting ATP synthase complex, catalytic core F(1) 1.04e-6 64 serine-type endopeptidase activity1.49e-4 151 endopeptidase activity 3.33e-4 16 structural constituent of ribosome
Islet specific KEGG enrichment P-value # Category 4.37e-6 16 Ribosome 3.26e-4 155 Oxidative phosphorylation
Islet specific miRNAs P-value # Category 6.65e-3 892 miR-30 family
High Fat Diet Islets • Running ISA on the 19 islet samples only • Only 8,288 probesets after filtering • Module #41 differentiates between HF/LF diets best: http://www2.unil.ch/cbg/Eurodia/isa5-html/maintable.html
High Fat Diet Islets • Condition scores significantly differ, p-value: 8.5*10-3 • Significantly enriched for serine-type endopeptidase activity, p-value: 3*10-12 • Enriched for regulation by Trypsin GTF, p-value: 3*10-14
High Fat Diet Islets • Module #41 • 58 probes, 45 Entrez genes • Two outliers
Acknowledgements UNIL CBG: Zoltán Kutalik Micha Hersch Aitana Morton Diana Marek Barbara Piasecka Bastian Peter Karen Kapur Alain Sewer Toby Johnson Armand Valsessia Gabor Csardi Sascha Dalessi KU Leuven: Leentje van Lommel Frans Schuit Thanks to EuroDia! http://serverdgm.unil.ch/bergmann
High Fat Diet Islets • Serine-type endopeptidase activity, GO molecular function category
High Fat Diet Islets • Intersection of module #41 and “Serine-type endopeptidase activity”, GO molecular function category